Dog days of summer arrive late, but with a chance of a heat wave


LEWISTON — Check your thermometers: If temperatures hit 90 degrees or higher Tuesday in the Lewiston-Auburn area it will be official — an official heat wave, that is.

A heat wave is three consecutive days of 90-degree temperatures or higher in the same area, according to National Weather Service Senior Meteorologist John Cannon.

The Twin Cities saw temperatures hit 92 degrees on Sunday and 90 on Monday. Most likely, the temperature will be at least 90 again on Tuesday, meeting the definition of “heat wave,” according to meteorologist James Brown, also of the National Weather Service in Gray.

The last heat wave on record in Maine was in Aug. 31 through Sept. 2, 2010, when temperatures hit 91 degrees. 

Other areas expected to experience a heat wave are the southwestern Maine and southern New Hampshire. 

On Monday, the coast had a “nice, cooling sea breeze,” Cannon said, but interior regions were sitting in the low 90s. 

“We have not only warm air near the surface … but also in the upper parts of the atmosphere,” Cannon said.

This same air mass will be overhead on Tuesday, bringing with it plenty of heat and humidity. 

“We’ve had very few hot spells for this year and last year, so it’s hot, but it’s just that it hasn’t happened for a while,” Cannon said. “That’s why people are feeling it.”

Tuesday is going to be a “carbon copy” of Monday, he said. There is a potential heat wave for interior sections, but the coast will probably not see a heat wave because of winds that may come out of the southeast on Wednesday that can bring breezes off the ocean for all areas, he said.

An air quality alert was issued for Maine from 11 a.m. until 11 p.m. Monday, Brown said. According to a Maine Department of Environmental Protection news release, ground-level ozone concentrations were expected to reach unhealthy levels on Monday and were expected to continue for Tuesday and possibly Wednesday.

“Early indications for Tuesday are that ozone levels would be unhealthy for the southwest coast, Midcoast and the high elevations of Acadia National Park, with moderate levels of ozone in the western interior, eastern interior and the Down East coast.”

Around Wednesday, we should see some relief from the heat as the air aloft gets cooler and drier, with temperatures dropping to the 70s and 80s for Thursday and Friday, Brown said. But with the cooler, drier air coming in on Wednesday, there will also be a trend to more thunderstorms toward the weekend, he said. 

Although this is one of the longest hot spells this summer, overall, the summer is trending to be a little bit cooler than normal, Brown said. And despite the severe thunderstorms that have occurred over the past few weeks, this summer is also trending to be slightly drier than normal.

“We’re a little bit behind in precipitation,” but above normal in terms of thunderstorms, Brown said. “It’s been an active summer with a lot of thunderstorms, but no records,” he said.

The Farmer’s Almanac called for thunderstorms, then turning fair for Aug. 16-19.

“We have a lot of warm air aloft, and that pretty much squashes any thunderstorm potential,” Cannon said. “Right now, it looks to be mainly sunny and dry and cooler,” for Saturday and Sunday, although there may be some heavy showers on Friday, he said. 

Fishing days are rated “poor” in the Farmer’s Almanac for Aug. 12-19. “They’ll either steal your bait or will not even touch your line,” but it is a good time to wax your floors, the almanac said.

Chris Williams contributed to this report.